Cooling device and multi-chamber heat treatment device

ABSTRACT

A cooling device configured to cool an article to be treated by immersing the article to be treated in coolant includes a cooling chamber configured to accommodate the article to be treated and store the coolant therein, a supply nozzle configured to supply the coolant into the cooling chamber from below the article to be treated, a recovery pipeline configured to collect the coolant stored in the cooling chamber from above the article to be treated, and a pump configured to pump the coolant collected by the recovery pipeline to the supply nozzle.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of International Application No. PCT/JP2015/069889, filed Jul. 10, 2015, which claims priority to Japanese Patent Application No. 2014-152048, filed Jul. 25, 2014. The contents of these applications are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a cooling device and a multi-chamber heat treatment device.

BACKGROUND

For example, Patent Document 1 discloses a multi-chamber heat treatment device including three heating devices and a single cooling device. In the multi-chamber heat treatment device, the heating devices and the cooling device are connected via intermediate conveyance chambers, and for example, an article to be treated heated by the heating devices is conveyed to the cooling device and cooled therein. In such a cooling device, for example, cooling of the article to be treated is performed by storing a coolant in the cooling chamber and immersing the article to be treated in the coolant in the cooling chamber. In addition, background art is also disclosed in the following Patent Documents 2 and 3.

DOCUMENTS OF THE RELATED ART Patent Documents [Patent Document 1]

Japanese Unexamined Patent Application, First Publication No. 2014-051695

[Patent Document 2]

Japanese Unexamined Patent Application, First Publication No. 2005-076101

[Patent Document 3] Japanese Unexamined Patent Application, First Publication No. H07-208400

SUMMARY

Incidentally, in order to improve a cooling speed of the article to be treated, circulating the coolant stored in the cooling chamber and forming a flow of the coolant in the cooling chamber during cooling of the article to be treated may be considered. In this case, in Patent Document 1, forming a flow of a coolant by supplying the coolant into the cooling chamber from a nozzle disposed beside the article to be treated while extracting the coolant from the cooling chamber through a drainage pipeline installed under the cooling chamber is considered.

However, the coolant heated by cooling the article to be treated flows toward an upper side of the cooling chamber. For this reason, in the above-mentioned method, a flow of the coolant supplied into the cooling chamber from the nozzle and a flow of the coolant that is heated to flow upward interfere with each other, the flow of the coolant in the cooling chamber becomes turbulent, and thus it is difficult to uniformly cool the article to be treated. In addition, since the coolant supplied from the nozzle is heated before arrival at the article to be treated, it is difficult to efficiently cool the article to be treated.

In consideration of the above-mentioned problems, the present disclosure is directed to provide a cooling device and multi-chamber heat treatment device that are configured to immerse an article to be treated in a coolant and cool the article to be treated in a cooling chamber, and capable of forming a flow of the coolant that can efficiently and uniformly cool the article to be treated in the cooling chamber.

In order to achieve the aforementioned objects, the following configurations are employed.

A the present disclosure is a cooling device configured to cool an article to be treated by immersing the article to be treated in coolant, the cooling device including: a cooling chamber configured to accommodate the article to be treated and store the coolant therein; a supply nozzle configured to supply the coolant into the cooling chamber from below the article to be treated; a recovery pipeline configured to collect the coolant stored in the cooling chamber from above the article to be treated; and a pump configured to pump the coolant collected by the recovery pipeline to the supply nozzle.

According to the present disclosure, in the cooling chamber, the coolant is supplied from below the article to be treated by the supply nozzle, the supplied coolant is collected from above the article to be treated by the recovery pipeline, and the collected coolant is pumped to the supply nozzle by the pump. For this reason, according to the present disclosure, a flow from below to above is formed in the cooling chamber by the supply nozzle, the recovery pipeline and the pump. Since such a flow is directed in the same direction as the coolant heated by cooling the article to be treated, generation of turbulence in the flow of the coolant in the cooling chamber can be suppressed. Accordingly, according to the present disclosure, the article to be treated can be uniformly cooled. In addition, the coolant supplied from the supply nozzle can be prevented from being heated before arrival at the article to be treated, and the article to be treated can be efficiently cooled. That is, according to the present disclosure, in the cooling device and the multi-chamber heat treatment device configured to immerse and cool the article to be treated in the coolant in the cooling chamber, a flow of the coolant capable of efficiently and uniformly cooling the article to be treated can be formed in the cooling chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first longitudinal cross-sectional view showing the entire configuration of a cooling device and a multi-chamber heat treatment device according to an embodiment of the present disclosure.

FIG. 2 is a longitudinal cross-sectional view showing the entire configuration of the cooling device according to the embodiment of the present disclosure.

FIG. 3A is a view taken along line A-A of FIG. 2.

FIG. 3B is a perspective view of a supply nozzle included in the cooling device according to the embodiment of the present disclosure.

FIG. 4A is a view showing an aspect of immersion cooling.

FIG. 4B is a view showing an aspect of mist cooling.

DETAILED DESCRIPTION

Hereinafter, an embodiment of an embodiment of a cooling device and a multi-chamber heat treatment device according to the present disclosure will be described with reference to the accompanying drawings. Further, in the following drawings, in order to increase members to recognizable sizes, scales of the members may be appropriately exaggerated.

As shown in FIG. 1, a multi-chamber heat treatment device including a cooling device of the embodiment is a device in which a cooling device R, an intermediate conveyance device H, and two heating devices (a heating device K1 and a heating device K2) are integrated. Further, the number of heating devices may be three.

The cooling device R is a device configured to cool an article to be treated X, and as shown in FIG. 1, includes a cooling chamber 1, a plurality of cooling nozzles 2, a plurality of mist headers 3, a cooling pump 4 (a pump), a cooling drain pipe 5, a cooling water tank 6, a cooling circulation pipe 7 (a recovery pipeline), a plurality of supply nozzles 8, a drain valve 9, and so on.

The cooling chamber 1 is a longitudinal cylindrical container (a container having a central axis in a vertical direction) configured to accommodate the article to be treated X, and an internal space is a cooling region RS. An upper portion of the cooling chamber 1 is connected to the intermediate conveyance device H, and an opening configured to bring the cooling region RS in communication with an internal space (a conveyance region HS) of the intermediate conveyance device H is formed in the cooling chamber 1. The article to be treated X is conveyed into the cooling region RS or unloaded from the cooling region RS via the opening. The cooling chamber 1 can store a coolant.

As shown in FIGS. 1 to 3B, the plurality of cooling nozzles 2 are disposed to be distributed around the article to be treated X accommodated in the cooling region RS. More specifically, the plurality of cooling nozzles 2 are disposed to be distributed around the article to be treated X such that the article to be treated X is enclosed as a whole and distances to the article to be treated X become preferably equal distances in a state in which a plurality of stages (specifically, five stages) are formed in a vertical direction and the stages are disposed at equal intervals in a circumferential direction of the cooling chamber 1 (the cooling region RS).

In addition, the plurality of cooling nozzles 2 are divided into a predetermined number of groups. That is, the plurality of cooling nozzles 2 are grouped at each stage in a vertical direction of the cooling region RS, and also grouped into a plurality of groups in a circumferential direction of the cooling chamber 1 (the cooling region RS). As shown in FIG. 2, the mist headers 3 are individually installed at the plurality of groups (nozzle groups).

Here, the coolant ejected from the cooling nozzles 2 is a liquid having a viscosity lower than that of cooling oil that is generally used for cooling of heat treatment, for example, water. A shape of injection holes of the cooling nozzles 2 is set such that the coolant such as water or the like becomes droplets having a uniform and constant particle diameter at a predetermined spray angle. In addition, as shown in FIGS. 1 to 5, spray angles of the cooling nozzles 2 and an interval of the neighboring cooling nozzles 2 are set such that droplets disposed at an outer circumferential side in the droplets ejected from the cooling nozzles 2 cross or collide with droplets disposed at the outer circumferential side and ejected from the neighboring cooling nozzles 2.

That is, the plurality of cooling nozzles 2 spray the coolant toward the article to be treated X such that the article to be treated X is entirely surrounded by an aggregate of droplets of the coolant, i.e., mist of the coolant (coolant mist).

The cooling device R of the embodiment can perform mist cooling of cooling the article to be treated X using such coolant mist, and cooling of immersing the article to be treated X in the coolant (immersion cooling). In the immersion cooling, the article to be treated X in the cooling chamber 1 is cooled in the immersion state by the coolant supplied from the plurality of supply nozzles 8. Further, cooling conditions such as a cooling temperature, a cooling time, or the like, in the cooling device R are appropriately set according to a purpose of heat treatment in the article to be treated X, a material of the article to be treated X, or the like.

The cooling pump 4 pumps the coolant remaining in the cooling water tank 6 to the mist headers 3 or the supply nozzles 8. Here, an opening/closing valve 31 is installed upstream from the mist headers 3, and an opening/closing valve 32 is installed upstream from the supply nozzles 8. When the mist cooling is performed, the opening/closing valve 32 is closed while the opening/closing valve 31 is opened, and the coolant is supplied from the cooling pump 4 to the cooling nozzles 2 installed at the mist headers 3. Meanwhile, when the immersion cooling is performed, the opening/closing valve 32 is opened while the opening/closing valve 31 is closed, and the coolant is supplied from the cooling pump 4 to the supply nozzles 8. Further, in the cooling pump 4, an ejection pressure of the coolant having small time fluctuation is preferably selected. In addition, a heat exchanger 30 is installed downstream from the cooling pump 4. The heat exchanger 30 cools the coolant ejected from the cooling pump 4 through heat exchange with a cooling medium. As the coolant is cooled by the heat exchanger 30, after the coolant collected from the cooling chamber 1 is cooled, the coolant is supplied into the cooling chamber 1 from the cooling nozzles 2 or the supply nozzles 8 again.

The cooling drain pipe 5 is a pipeline configured to bring a lower portion of the cooling chamber 1 and the cooling water tank 6 in communication with each other, and the drain valve 9 is installed in the middle of the pipeline. The cooling water tank 6 is a liquid container configured to store coolant drained from the cooling chamber 1 via the cooling drain pipe 5 or the cooling circulation pipe 7. As shown in FIG. 2, the cooling circulation pipe 7 is a pipeline configured to bring an upper portion of the cooling chamber 1 and an upper portion of the cooling water tank 6 in communication with each other. The cooling circulation pipe 7 is configured to return the coolant that overflows from the cooling chamber 1 upon the above-mentioned immersion cooling into the cooling water tank 6. That is, the cooling circulation pipe 7 collects the coolant stored in the cooling chamber 1 from above the article to be treated X accommodated in the cooling chamber 1.

FIG. 3A is a view taken along line A-A of FIG. 2. As shown in FIG. 3A, the plurality of supply nozzles 8 are disposed to be distributed at a lower portion of the cooling chamber 1, and the coolant is supplied into the cooling chamber 1 by injecting the coolant upward upon the immersion cooling. The plurality of supply nozzles 8 supply the coolant upward into the cooling chamber 1 from below the article to be treated X accommodated in the cooling chamber 1.

FIG. 3B is a perspective view of the supply nozzle 8. As shown in FIG. 3B, the supply nozzle 8 is constituted by a tubular body having through-holes 8 b through which an upper end becomes an opening end 8 a from which coolant is ejected and passing both sides thereof. The supply nozzle 8 introduces the surrounding coolant from the through-hole 8 b and ejects the coolant from the opening end 8 a at a flow rate of several times that of the coolant supplied from the lower end when the coolant supplied from the lower end is ejected from the opening end 8 a of the upper end.

Returning to FIG. 1, the intermediate conveyance device H includes a conveyance chamber 10, a conveyance chamber placing table 11, a cooling chamber elevation table 12, a cooling chamber elevation cylinder 13, a pair of conveyance rails 14, a pair of pusher cylinders (a pusher cylinder 15 and a pusher cylinder 16), a heating chamber elevation table 17, a heating chamber elevation cylinder 18, and so on. The conveyance chamber 10 is a container installed between the cooling device R, the heating device K1 and the heating device K2, and the internal space of the conveyance chamber 10 is the conveyance region HS. The article to be treated X is loaded by an external conveyance device or loaded into the conveyance chamber 10 from a conveyance port (not shown) while accommodated in the container, which may be a basket or the like.

The conveyance chamber placing table 11 is a support frame configured to close a delivery port between the cooling chamber 1 and the conveyance chamber 10 when the article to be treated X is cooled by the cooling device R, and another article to be treated X can be placed thereon. The cooling chamber elevation table 12 is a support frame on which the article to be treated X is placed when the article to be treated X is cooled by the cooling device R, and supports the article to be treated X such that a bottom section of the article to be treated X is preferably widely exposed. The cooling chamber elevation table 12 has a plurality of through-holes 12 a (see FIG. 3A) opened to match the supply nozzles 8, and is fixed to a distal end of a movable rod of the cooling chamber elevation cylinder 13.

The cooling chamber elevation cylinder 13 is an actuator configured to vertically move (elevate) the cooling chamber elevation table 12. That is, the cooling chamber elevation cylinder 13 and the cooling chamber elevation table 12 are an exclusive conveyance device of the cooling device R, and the article to be treated X placed on the cooling chamber elevation table 12 is conveyed from the cooling region RS to the conveyance region HS while being conveyed from the conveyance region HS to the cooling region RS.

The pair of conveyance rails 14 are installed at a floor section in the conveyance chamber 10 to extend in a horizontal direction. The conveyance rails 14 are guide members used when the article to be treated X is conveyed between the cooling device R and the heating device K1. The pusher cylinder 15 is an actuator configured to press the article to be treated X when the article to be treated X in the conveyance chamber 10 is conveyed toward the heating device K1. The pusher cylinder 16 is an actuator configured to press the article to be treated X when the article to be treated X is conveyed from the heating device K1 to the cooling device R.

That is, the pair of conveyance rails 14, the pusher cylinder 15 and the pusher cylinder 16 are an exclusive conveyance device configured to convey the article to be treated X between the heating device K1 and the cooling device R. Further, while the pair of conveyance rails 14, the pusher cylinder 15 and the pusher cylinder 16 are shown in FIG. 1, the intermediate conveyance device H in reality includes the total of two conveyance rails 14, the pusher cylinder 15 and the pusher cylinder 16. That is, the conveyance rails 14, the pusher cylinder 15 and the pusher cylinder 16 are also provided for not only the heating device K1 but the heating device K2. Further, when a third heating device is installed, a total of two pairs of conveyance rails 14, the pusher cylinder 15 and the pusher cylinder 16 are provided.

The heating chamber elevation table 17 is a support frame on which the article to be treated X is placed when the article to be treated X is conveyed from the intermediate conveyance device H to the heating device K1. That is, the article to be treated X is conveyed directly over the heating chamber elevation table 17 as the article to be treated X is pressed by the pusher cylinder 15 in a rightward direction of FIG. 1. The heating chamber elevation cylinder 18 is an actuator configured to vertically move (elevate) the article to be treated X on the heating chamber elevation table 17. That is, the heating chamber elevation table 17 and the heating chamber elevation cylinder 18 are an exclusive conveyance device for the heating device K1, and the article to be treated X placed on the heating chamber elevation table 17 is conveyed from the conveyance region HS into the inside (a heating region KS) of the heating device K1 and simultaneously conveyed from the heating region KS to the conveyance region HS.

Since the heating device K1 and the heating device K2 have basically the same configuration, hereinafter, a configuration of the heating device K1 will be described representatively. The heating device K1 includes a heating chamber 20, an insulation container 21, a plurality of heating heaters 22, a vacuum exhaust pipe 23, a vacuum pump 24, an agitating blade 25, an agitating motor 26, and so on.

The heating chamber 20 is a container installed on the conveyance chamber 10, and an internal space of the heating chamber 20 is the heating region KS. While the heating chamber 20 is a longitudinal cylindrical container (a container having a central axis is in a vertical direction) like the above-mentioned cooling chamber 1, the heating chamber 20 has a size smaller than that of the cooling chamber 1. The insulation container 21 is a longitudinal cylindrical container installed in the heating chamber 20, and formed of an insulating material having predetermined insulation performance.

The plurality of heating heaters 22, each of which is a rod-shaped heat generating body, are installed inside the insulation container 21 in a vertical posture and at predetermined intervals in a circumferential direction. The plurality of heating heaters 22 are configured to heat the article to be treated X accommodated in the heating region KS to a predetermined temperature (heating temperature). Further, a heating condition such as a heating temperature, a heating time, or the like, is appropriately set according to a purpose of heat treatment related to the article to be treated X, a material of the article to be treated X, or the like.

Here, the heating condition includes a vacuum level (a pressure) in the heating region KS (the heating chamber 20). The vacuum exhaust pipe 23 is a pipeline in communication with the heating region KS, and has one end connected to an upper portion of the insulation container 21 and the other end connected to the vacuum pump 24. The vacuum pump 24 is an exhaust pump configured to suction air in the heating region KS via the vacuum exhaust pipe 23. A vacuum level in the heating region KS is determined by an exhaust amount of the air from the vacuum pump 24.

The agitating blade 25 is a rotary blade installed at an upper portion in the insulation container 21 in a posture in which a direction of the rotary shaft is in a vertical direction (an upward/downward direction). The agitating blade 25 agitates the air in the heating region KS as the agitating blade 25 is driven by the agitating motor 26. The agitating motor 26 is a rotary driving source installed on the heating chamber 20 such that an output shaft is in a vertical direction (an upward/downward direction). The output shaft of the agitating motor 26 disposed on the heating chamber 20 is axially coupled to the rotary shaft of the agitating blade 25 disposed in the heating chamber 20 such that air-tightness (sealability) of the heating chamber 20 is not damaged.

Further, the multi-chamber heat treatment device according to the embodiment includes a control panel (a control device) that is not shown. The control panel includes a manipulation unit on which a user sets and inputs various conditions of heat treatment, and a control unit configured to perform heat treatment according to information related to the various conditions that are set and input as described above with respect to the article to be treated X by controlling drive units such as the cooling pump 4, the heating heaters 22, various cylinders, the vacuum pump 24, and so on, based on a control program that is previously stored therein.

Next, an operation of the multi-chamber heat treatment device configured as described above, in particular, an operation of the cooling device R, will be described in detail. An operation of the multi-chamber heat treatment device is autonomously performed by the control panel based on setting information. Further, as is well known, heat treatment includes various kinds of treatments according to purposes. Hereinafter, as an example of the heat treatment, an operation in the case in which the article to be treated X is treated through quenching will be described.

The quenching is completed by, for example, heating the article to be treated X to a temperature T1, rapidly cooling the article to be treated X to a temperature T2, maintaining the article to be treated X at the temperature T2 for a constant time, and then slowly cooling the article to be treated X. The article to be treated X loaded by the external conveyance device or accommodated in the intermediate conveyance device H from the conveyance port is conveyed onto the heating chamber elevation table 17 by, for example, operating the pusher cylinder 15, and is accommodated in the heating region KS by further operating the heating chamber elevation cylinder 18.

Then, when the article to be treated X is heated to the temperature T1 by applying electricity to the heating heaters 22 for a constant time, the article to be treated X is conveyed onto the cooling chamber elevation table 12 by operating the heating chamber elevation cylinder 18 and the pusher cylinder 16, and conveyed to the cooling region RS by further operating the cooling chamber elevation cylinder 13.

Here, when the immersion cooling is performed, as shown in FIG. 4A, the opening/closing valve 31 of the mist headers 3 is closed while the opening/closing valve 32 disposed upstream from the supply nozzles 8 is opened, and further, the drain valve 9 is also closed. Then, as the cooling pump 4 is previously operated to supply the coolant from the plurality of supply nozzles 8, the inside of the cooling region RS is filled with a coolant W. Even in a state in which the article to be treated X is immersed, the coolant W is continuously supplied into the cooling chamber 1 from the supply nozzles 8. Then, the coolant W continuously supplied from the supply nozzles 8 cools the article to be treated X and rises in the cooling chamber 1, and the coolant W that overflows is collected by the cooling circulation pipe 7 to be stored in the cooling water tank 6. In addition, the coolant W stored in the cooling water tank 6 is supplied into the cooling chamber 1 from the supply nozzles 8 by the cooling pump 4 again. Here, the coolant W is cooled by the heat exchanger 30.

Meanwhile, when the mist cooling is performed, as shown in FIG. 4B, the opening/closing valve 31 of the mist headers 3 is opened while the opening/closing valve 32 disposed upstream from the supply nozzles 8 is closed, and the drain valve 9 is opened. Then, the coolant W is sprayed from the cooling nozzles 2 toward the article to be treated X through the mist headers 3. Accordingly, the article to be treated X is treated through the mist cooling by droplets of the coolant W injected from the cooling nozzles 2. In addition, the coolant W that drops onto the bottom section of the cooling chamber 1 is stored in the cooling water tank 6 through the cooling drain pipe 5. In addition, the coolant W stored in the cooling water tank 6 is sprayed into the cooling chamber 1 from the cooling nozzles 2 of the mist headers 3 by the cooling pump 4 again. Here, the coolant W is cooled by the heat exchanger 30.

According to the multi-chamber heat treatment device including the cooling device R of the above-mentioned embodiment, in the cooling chamber 1, the coolant W is supplied from below the article to be treated X by the supply nozzles 8, the supplied coolant W is collected from above the article to be treated X by the cooling circulation pipe 7, and the collected coolant W is pumped to the supply nozzles 8 by the cooling pump 4. For this reason, according to the multi-chamber heat treatment device including the cooling device R of the embodiment, a flow from below to above is formed in the cooling chamber 1 by the supply nozzles 8, the cooling circulation pipe 7 and the cooling pump 4. Since such a flow is directed in the same direction as the coolant W heated by cooling the article to be treated X, generation of turbulence of the flow of the coolant W in the cooling chamber 1 can be suppressed. Accordingly, according to the multi-chamber heat treatment device including the cooling device R of the embodiment, the article to be treated X can be uniformly cooled. In addition, the coolant W supplied from the supply nozzles 8 can be prevented from being heated before arrival at the article to be treated X, and the article to be treated X can be efficiently cooled. Accordingly, according to the multi-chamber heat treatment device including the cooling device R of the embodiment, a flow of the coolant W capable of efficiently and uniformly cooling the article to be treated X can be formed in the cooling chamber 1.

In addition, in the multi-chamber heat treatment device including the cooling device R of the embodiment, each of the supply nozzles 8 is a tubular body having the opening end 8 a configured to eject the coolant W at an upper end thereof, and the through-holes 8 b passing through both sides thereof. For this reason, the supply nozzles 8 can introduce the surrounding coolant from the through-holes 8 b, and eject the coolant W from the opening end 8 a at a flow rate of several times that of the coolant W supplied from the lower end. Accordingly, more efficient cooling can be performed by increasing a flow velocity of the coolant W in the cooling chamber 1.

In addition, in the multi-chamber heat treatment device including the cooling device R of the embodiment, the heat exchanger 30 configured to cool the coolant W collected by the cooling circulation pipe 7 is provided. For this reason, in comparison with the case in which the coolant W is simply circulated, the article to be treated X can be cooled in a shorter time.

While an appropriate embodiment has been described above with reference to the accompanying drawings, the present disclosure is not limited to the embodiment. All shapes, combinations, and so on, of the components shown in the above-mentioned embodiment are exemplified, and various modifications based on design requirements and so on may be made without departing from the scope of the present disclosure.

For example, in the embodiment, while the multi-chamber heat treatment device including the cooling device R, the intermediate conveyance device H and the two heating devices has been described, the present disclosure is not limited thereto. The present disclosure can also be applied to a multi-chamber heat treatment device having, for example, a type in which the cooling device R and a single heating chamber are adjacent to each other with a swing door therebetween.

In addition, while the article to be treated X is accommodated in the cooling region RS from above in the cooling device R of the embodiment, the present disclosure is not limited thereto. The present disclosure can be applied to a case in which the article to be treated X is accommodated in the cooling region RS from a side portion (in a horizontal direction) or a lower side.

In addition, the cooling device R of the embodiment has been described as enabling the mist cooling. However, the present disclosure is not limited thereto but may be applied to a cooling device that does not perform the mist cooling.

INDUSTRIAL APPLICABILITY

According to the present disclosure, in the cooling device and multi-chamber heat treatment device configured to immerse and cool the article to be treated in the coolant in the cooling chamber, a flow of the coolant capable of efficiently and uniformly cooling the article to be treated can be formed in the cooling chamber. 

What is claimed is:
 1. A cooling device configured to cool an article to be treated by immersing the article to be treated in coolant, the cooling device comprising: a cooling chamber configured to accommodate the article to be treated and store the coolant therein; a supply nozzle configured to supply the coolant into the cooling chamber from below the article to be treated; a recovery pipeline configured to collect the coolant stored in the cooling chamber from above the article to be treated; and a pump configured to pump the coolant collected by the recovery pipeline to the supply nozzle, wherein the supply nozzle is constituted by a tubular body having an upper end serving as an opening end through which the coolant is ejected and through-holes passing through both sides thereof.
 2. The cooling device according to claim 1, comprising a heat exchanger configured to cool the coolant collected by the recovery pipeline.
 3. A multi-chamber heat treatment device comprising: a heating device configured to heat an article to be treated; and a cooling device according to claim
 1. 4. A multi-chamber heat treatment device comprising: a heating device configured to heat an article to be treated; and a cooling device according to claim
 2. 